Personal experience- Ziffit is an absolute SCAM
I had a terrible experience using Ziffit. I hope this review will deter anyone reading this from ever using their services.
I`m a graduate student who entrusted Ziffit with the sale of my books this January. Ziffit is profiting off students by its deceptive and illegal business practices. First, they will conduct an arbitrary "quality inspection" on your books. Second, if your books fail to meet this standard, they will KEEP YOUR BOOKS WITHOUT PROVIDING COMPENSATION. Third, they will NOT PROVIDE A REASON as to why your book "failed" the quality inspection.
I had two expensive law school supplements (purchased for around $200 total) which were in good condition, but were rejected. I was supposed to receive approximately $45, but I RECEIVED $0 and was informed that my books had been "RESPONSIBLY RECYCLED" without my permission. When I asked why my books failed to meet the quality check, I was informed that they had already recycled my books. They refused to provide any photos or evidence as to why my books had failed the check. They failed to return my books, and they failed to compensate me as we had agreed.

Here`s a copied and pasted email I received from one of the customer service individuals:

"When items arrive with us, their condition is inspected by our team. Our business sells books on and if they are not in a good condition, we are unable to sell them. On these occasions, we responsibly recycle these books. Selling these items on would be a breach of our legal obligation – so rejected items are never put up for resale... Unfortunately, these items (my books) have already been recycled so we are unable to provide images. "

To add insult to injury, they will copy and paste their "terms and conditions" which includes language such as:
6.1 Reasons for rejection: we reserve the right to, at our sole discretion, reject items and/or cancel or amend your order where:

(e) one or more of the items was listed at an incorrect price due to a typographical error (or an error in the pricing information stated by us).

They operate based on an illegal contract. The nuance is that if Ziffit makes an error, you as the consumer pays the price. Ziffit will keep your property and refuse to pay you and pretend this is a legal clause. Which it is not.

Another interesting clause:

If a court finds part of the terms illegal, the rest will continue in force: Each of the sections in these terms operates separately. If any court or relevant authority decides that any of them are unlawful, the remaining sections will remain in full force and effect.

Even the individual who drafted this contract KNOWS this contract is completely illegal.
I could go on but I`m sorely disappointed and appalled that these horrible companies that rip off students in debt even exist. I hope this is a fair and true warning to anyone reading this.

Sincerely,

Disgruntled consumer